Ducted Heating and Cooling System

ABSTRACT

A heating and cooling system or installation for heating or cooling air within a building space, including a water chiller for chilling water and a coil to which the chilled water can be delivered. Air can then be driven by a fan through the coil to cool the air and the cooled air can be delivered into the building space for cooling the building space. The system can include a water heating facility to heat water that is delivered to the coil so that air driven through the coil can be heated. The coil is connected to ducting for delivering cooled or heated air to the building space.

PRIORITY CROSS-REFERENCE

The present application claims priority from Australian ProvisionalPatent Application No. 2018901339 filed 23 Apr. 2018 and AustralianProvisional Patent Application No. 2018902927 filed 10 Aug. 2018 thecontents of which are to be considered to be incorporated into thisspecification by this reference.

TECHNICAL FIELD

The present invention relates to ducted heating and cooling systems forheating and cooling domestic dwellings and commercial buildings. Thepresent invention has been developed principally for domestic dwellingsand it will be convenient to describe the invention in relation to thatuse, although it should be appreciated that the invention can havebroader application to commercial buildings and factories etc.

BACKGROUND OF INVENTION

The discussion of the background to the invention that follows isintended to facilitate an understanding of the invention. However, itshould be appreciated that the discussion is not an acknowledgement oradmission that any aspect of the discussion was part of the commongeneral knowledge as at the priority date of the application.

Domestic heating and cooling systems in Australia are often ductedsystems and the present invention is directed to that type of system.Such systems typically utilise a ducted gas heater for the heating partof the system and refrigerated cooling for the cooling part of thesystem and heated or cooled air is distributed about the dwelling viacommon ducting. This means that advantageously, a single ducting set-upcan be used for distributing both heated and cooled air. In thesearrangements, the single ducting set-up is separately connected toseparate heating and cooling devices or appliances and the arrangementis that only one of the devices or appliances is operational at any onetime to supply heated or cooled air to the ducting. Because thisarrangement conveniently means that only one ducting set-up is requiredto be installed in the dwelling, there is thus significant savings oncost and space, and also reductions in the aesthetic impact of increasednumbers of ducting outlets, which would be required if separate ductingwas installed for separate heating and cooling units.

Refrigerated cooling systems generally include an outdoor compressorunit and an indoor coil unit connected together by refrigerant copperpiping. The outdoor compressor unit condenses refrigerant and pumps itto the coil where it expands to create the cooling effect. Air isfan-driven through the coil to cool the air and the cooled air isdischarged into the dwelling through the ducting. The manner in whichrefrigerated cooling operates is well known and does not need to bediscussed further herein.

The compressor unit of a refrigerated cooling installation can beexpensive to operate with larger sized compressor units requiring athree phase power supply. For this reason and to minimise or reduceexpense, the power rating of the compressor unit is usually selected tobe less than the power rating of the heating unit. To compensate forthis, the cooling unit usually operates on “day/night” zoning wherebycooling is restricted in daytime to rooms of the dwelling that arecommonly used during the day (kitchen, lounge areas etc.) and in nighttime to the bedrooms of the dwelling. In contrast, the heating unit,which is less expensive to run, can operate to heat the entire dwellingwhenever it is used. By operating in this manner, the refrigeratedsystem or the compressor unit can have a power rating of about 60% ofthe heating unit.

Thus, in a typical ducted heating and cooling system, a 20 kW heatingunit would commonly be matched with a 12 kW refrigerated system orcompressor unit. Likewise, a 30 kW heating unit would commonly bematched with a 14 kW or 17 kW compressor unit and a 35 kW heating unitwould commonly be matched with a 20 kW compressor unit. In each case,the refrigerated system has a reduced power rating compared to theheating system.

Arrangements of the above kind have operated successfully over manyyears. In particular, the use of refrigerated cooling is favoured bymany dwelling owners given the high cooling effect that it can achieveand the speed at which cooling is achieved. However, the cost of runningrefrigerated cooling is a disincentive when compared to other forms ofcooling (evaporative cooling for example) and with energy costscontinuously rising, alternative options for cooling that do not userefrigeration are being pursued. The present invention has beendeveloped with this in mind.

SUMMARY OF INVENTION

The present invention provides a heating and cooling system orinstallation for heating or cooling air within a building space. Aheating and cooling system or installation according to the presentinvention can take various forms, but each form includes a water chillerfor chilling water and a coil to which the chilled water can bedelivered. Air can then be fan driven through the coil to cool the airand the cooled air can be delivered into the building space for coolingthe building space.

In a first form of the present invention, there is provided a heatingand cooling system or an installation for heating or cooling air withina building space, the system including:

-   -   a. a heating device which is operational to heat air, and a        cooling device,    -   b. a fan, and    -   c. ducting comprising delivery ducting through which air heated        by the heating device or cooled by the cooling device can be        delivered into the building space and return ducting through        which air within the building space can be returned to the        heating and cooling devices,

the cooling device comprising a water chilling system having a coilwhich is operational to cool air passing through it and each of theheating device and the coil having an air inlet and an air outlet, theair inlet of one of the heating device and the coil being connected tothe return ducting, and the air outlet of that device being connected tothe air inlet of the other of the heating device and the coil,

the water chilling system further including a water chiller which is inclosed loop connection with the coil to deliver chilled water to thecoil and to receive water from the coil,

the system being operable such that operation of the fan causes air flowthrough the return ducting from the building space, then through theheating device and the coil, and the delivery ducting for delivery intothe building space, and the system further being operable such that onlyone of the heating and the cooling devices is operational at any onetime.

In a second form of the present invention, there is provided a heatingand cooling system for heating or cooling air within a building space,the system including:

-   -   a. a water heating facility to heat water,    -   b. a water chiller to cool or chill water,    -   c. a coil in fluid connection with water heating facility and        the water chiller and through which air can be passed for        heating or cooling,    -   d. a fan for driving air through the coil, and    -   e. ducting comprising delivery ducting through which air which        has been heated or cooled by the coil can be delivered into the        building space and return ducting through which air within the        building space can be returned to the coil for heating or        cooling,

the system being operable such that the water heating facility or thewater chiller supplies either heated or cooled or chilled water to thecoil and the fan causes air to flow through the return ducting from thebuilding space, then through the coil, and then through the deliveryducting for delivery into the building space.

Each of the first and second forms of the invention each adopt a waterchiller for cooling or chilling water and a coil to which the cooled orchilled water is delivered and through which air is fan driven for thepurpose of cooling the air. This use of a water chiller (as will becomeevident below) is unique in heating and cooling systems or installationsand provides surprising benefits.

The expression “cooled or chilled water” and variations are not intendedto imply a significant difference between water that is cooled ascompared to water that is chilled. The expression is intended to captureany use of a water chiller that lowers the temperature of water that isdelivered to the water chiller for subsequent delivery to a coil andrecognises that the temperature of water that exits the water chillercan vary depending on the level of cooling of the building space that isrequired. For this reason, cooled water might be considered to be of ahigher temperature than chilled water, and so the expression is intendedto capture water of any temperature that exits the water chiller andthat is of a lower temperature than the temperature of water that isdelivered to the water chiller.

The present applicant is not aware that prior art ducted gas heating andcooling systems have previously employed water chilling systems(comprising a water chiller and a coil) for the purpose of cooling fandriven air. The prior art in ducted cooling systems is all directed torefrigerated or evaporative cooling. Water chillers have not heretoforebeen considered, let alone employed. Moreover, the present applicant hasdiscovered, surprisingly, that the use of water chillers can providesignificant advantages compared to the use of refrigerated cooling. Amajor advantage as discussed below, has been identified in relation tothe reduced energy usage that can be realised.

It has been discovered that the power rating or the kW output(hereinafter “power rating”) of the water chilling system that is usedin the invention and that can deliver cooling in a similar manner tothat provided by refrigerated air conditioning, can be less than thepower rating that is required by a refrigerated air conditioning system.In other words, the power rating of the water chilling system can besmaller or lesser than the power rating of a refrigerated system and canthus provide reduced energy consumption and therefore running costsavings on that basis.

For example, where a 20 kW heating unit would be matched with a 12 kWrefrigerated system, the invention allows a 7 kW water chilling systemto be employed. This reduction in power rating occurs throughout thepairings given above between heating units and refrigerated systems sothat, a 30 kW heating unit could be matched with a 10 kW water chillingsystem, and a 35 kW heating unit could be matched with a 12 kW waterchilling system. This represents a possible 40% reduction in energyconsumption by the use of a water chilling system as compared torefrigerated air conditioning system, with an overall similar coolingeffect. This reduction in energy consumption is significant, unexpectedand highly beneficial to consumers by reduced energy cost, and energyproviders, given that in many cities, power usage for air conditioningduring extreme heat events often peaks and causes power outages.

Beneficially, the use of reduced power rating water chilling systemsdoes not require an increase in the speed or volume of airflow acrossthe coil. Rather, the airflow that is generated to flow across a coil ofa 12 kW refrigerated cooling system can be maintained to flow across thecoil of a 7 kW water chilling system. This represents a velocity of airflow for the coil of a 7 kW water chilling system that is greater thanwould ordinarily applied to a 7 kW coil. Thus, a fan of an existingheating or cooling facility or device can be used to drive air throughthe coil of the water chilling system at the same speed as it normallydrives in the system prior to the introduction of the water chillingsystem. It follows that the power consumption of the fan that drivesairflow through the system does not need to change. However, it is anoption for the actual surface area of the coils over which air flows canbe increased to enhance the cooling performance of the chiller unit.

A heating and cooling system or installation according to the inventionadvantageously thus provides significant benefits over the use ofrefrigerated cooling (that employs a refrigerant) in terms of:

-   -   energy efficiency and running costs—the same cooling effect can        be achieved using significantly lower energy because the power        requirement for a water chiller will be less than that of a        refrigerated cooler and thus will result in lower running costs,    -   capital cost—the cost of a reduced power rating water chiller        system will cost less to purchase than a higher power rating        refrigerated system,    -   maintenance cost—because the water chilling system will use        water as the chilling medium rather than refrigerant, the        maintenance program will be less complex because working with        and replacing water is easier than with refrigerant and        refrigerant is expensive and therefore maintenance of a water        chilling system will be less costly, and    -   environmental benefit—refrigerant gases are CO₂ greenhouse gases        and thus contribute to greenhouse gas emissions. Water is not a        greenhouse gas and so the use of water therefore can contribute        to a reduction in greenhouse gas emissions.

The above advantages are expected to be not only highly attractive toconsumers, particularly in relation to the expected running costreductions, but also in relation to Governments that are aiming toreduce greenhouse gas emissions and energy suppliers that are alreadystretched in relation to the supply of energy during days of extremeheat events.

In the first form of the invention, the air inlet of the heating devicecan be connected to the return ducting, so that air that is returnedfrom the building space flows into the heating device first and theninto the coil of the cooling device. In this arrangement, the heatingdevice is positioned upstream of the coil. In other forms of theinvention, the air inlet of the coil is connected to the return ducting,so that air that is returned from the building space flows into the coilfirst and then into the heating device. In this arrangement, the coil ispositioned upstream of the heating device. Thus either arrangement ispossible.

In the first form of the invention, the fan can be a separate component,or it can be a component that is integrated into the heating device orthe cooling device. The preference is for the heating device to includea fan. Based on this preference, it is also preferred that the heatingdevice is positioned upstream of the cooling device so that the heatingdevice is connected to the return ducting. In this manner, with theheating device including an integrated fan, the fan is operable to drawair into the heating device from the return ducting and to push itthrough the heating device and into the coil and thereafter through thedelivery ducting. In an alternative arrangement, a separate fan or fanscan be provided in addition to the fan that is integrated into theheating device.

In either form of the invention, the fan can be a component that isseparated from the coil, or it can be a part of a fan/coil unit, orintegrated with the coil, or simply attached to the coil. The preferenceis for the fan to be connected to or integrated with the coil so thatthe fan and the coil form a single complete fan/coil unit. Thissimplifies the ducting as it means that the delivery ducting can connectto an outlet of the fan/coil unit and the return ducting can connect toan inlet of the fan/coil unit and no intermediate ducting between thefan and the coil is required.

The further preference, is that the fan connects to the return ductingor is positioned on the side of the return ducting and that the coilconnects to the delivery ducting is be positioned on the side of thedelivery ducting, so that the fan is positioned upstream of the coil. Bythis arrangement, the fan is operable to draw air into the coil from thereturn ducting and to push it through the coil and thereafter throughthe delivery ducting.

Where the fan is a separate component to the coil, ducting can extendbetween the fan and the coil to connect them. The fan can be upstream ordownstream of the coil, but, as indicated above, the preference would befor the fan to be upstream of the coil.

Depending on the volume of airflow required, more than a single fan canbe provided. These can be arranged in series. Moreover, it is possiblefor a first fan to be provided connected to or integrated with the coilto form a fan/coil unit and for a second and further fans to be added asnecessary. The second and further fans could be connected to thefan/coil unit by ducting.

The fan can be operated independently of the heating/cooling facilitiesor the heating/cooling devices or it can be operational automaticallyupon operation of the facilities or devices. Automatic operation of thefan is preferred to ensure that the fan always operates when thefacilities or devices are operating.

The fan or fan/coil unit can incorporate air filters for filtering theair that flows through the heating/cooling facility. The fan or fan/coilunit can also incorporate fresh air intake.

In either form of the invention, the heating device or the water heatingfacility can be of any suitable kind such as electric or gas, althoughgas is preferred. The device or the facility is operational when theelectric heating element or the gas flame is activated.

In either form of the invention, the water that is chilled by the waterchiller can include additives. Suitable additives can includeanti-freeze additives where the water chiller is to be deployed inregions prone to sub-zero Celsius conditions.

In either form of the invention, the water chiller can be in closed loopconnection with the coil, so that the water that is chilled by thechiller is quarantined within the water chiller, the coil and the feedand return conduits that connect the water chiller with the coil. It isnot intended that the water be used other than through this loop.

In either form of the invention, the water chiller can be operationalwhen water is being chilled and being fed through the feed conduits tothe coil for circulation within the coil. The chilled water willcirculate through the coil for a period that relates to the capacity ofthe coil and the speed of the water flow. A pump will be located at thewater chiller to pump the water to the coil and the displacement ofwater by the pump from the chiller will cause the water to circulateabout the coil and eventually return to the chiller.

In either form of the invention, the water chiller can control thetemperature to which the water within the chiller is chilled. The watercan be chilled to a low temperature at the commencement of a coolingprocess, and once the set or desired cooled temperature in the buildingspace has been reached or has been closely or sufficiently approached,the temperature to which the water is chilled can be adjusted upwardlyas required to maintain the cooled temperature as achieved. Testing hasshown that pre-chilling the water within the water chiller to about 6-7°C. prior to activating the fan can improve initial temperaturereduction.

In either form of the invention, the cooled temperature within thebuilding space can also be controlled by fan speed to adjust the airflowacross or circulating through the coil. Thus, for controlling the cooledtemperature within the building space, one or both of adjusting thetemperature to which the water is chilled and controlling the fan can beemployed. Similar adjustment and control will apply when heating abuilding space.

In either form of the invention, the chilled water coil can be of anysuitable kind.

In the first form of the invention, the heater and the chilled watercoil can be housed in the one housing or cabinet. This differs fromexisting systems in which the heater is located or housed separately tothe coil of the refrigerated unit due to space constraints in the roofspace of a dwelling. This arrangement provides advantages in that boththe heater and the chilled water coil can be assembled within the onehousing or cabinet prior to installation within the roof space.

In the second form of the invention, the water heating facility can bein closed loop connection with the coil, so that the water that isheated is quarantined within the heating facility, the coil and the feedand return conduits that connect the heating facility with the coil. Itis not intended that the water be used other than through this loop.

In the second form of the invention, there could be a single feedconduit that connects the water heating facility and the water chillerwith the coil and a single return conduit that connects the coil withthe water heating facility and the water chiller. Alternatively, therecan be separate feed and return conduits that connect the water heatingfacility and the water chiller with the coil. Still further, there canbe common feed and return conduits that connect with the coil, withbranch conduits connecting to the common conduits and separatelyconnecting to the separate water heating facility and water chiller.Suitable valving can be employed where the branch conduits connect tothe common conduits so that there can only be one flow of either heatedor cooled water to the coil at any one time.

In either form of the invention, the water heating facility and/or thewater chiller are operational to feed heated or cooled water through afeed conduit or conduits to the coil for circulation within the coil.The water will circulate through the coil for a predetermined periodthat can be dependent on factors such; as the level of heating orcooling required, the capacity of the coil, the speed of the water flowand the airflow output of the fan. A pump or pumps can be employed topump the water to the coil and the displacement of water by the pumpfrom the water heating facility and/or the water chiller will cause thewater to circulate about the coil and eventually return to the waterheating facility and/or the water chiller. Where the heating/coolingdevices of the first form of the invention or the water heating facilityand the water chiller of the second form of the invention are separatecomponents, a pump can be associated with each. Alternatively, a singlepump can service each of the components, particularly where theheating/cooling devices of the first form of the invention or the waterheating facility and the water chiller of the second form of theinvention are connected or integrated into a single unit or device.

The water heating facility and the water chiller can control thetemperature to which the water is heated or cooled. The water can beconditioned to a high temperature at the commencement of a heatingprocess, or to a low temperature at the commencement of a coolingprocess, and once the set or desired temperature in the building spacehas been reached or has been closely or sufficiently approached, thetemperature to which the water is heated or cooled can be adjusteddownwardly or upwardly as required to maintain the desired temperature.In respect of cooling, testing has shown that pre-chilling the waterwithin the water chiller to about 6-7° C. prior to activating the fancan improve initial temperature reduction.

An advantage of the present invention is that in some forms, only thefan and the coil need to be housed within the roof space of a dwelling.This differs from prior art arrangements in which both a heater and acoil are housed within the roof space so that more space is required inthe roof space than is envisaged to be required for the heating andcooling system of the present invention.

An additional advantage of the present invention is the capability toadd further energy saving devices such as PV solar panels, hot watersolar collectors and hot/cold water storage.

In one respect, the invention has been developed following the discoverythat conventional refrigerated air conditioning used for coolingpurposes can be replaced with a water cooling or chilling systemembodying a water chiller to achieve substantially the same coolingeffect at a reduced power consumption and other associated benefits.

In a specific example as explained above, the power rating of the waterchilling system can be about 40% less than the power rating of therefrigerated air conditioning system that would ordinarily be pairedwith the heating unit of a ducted heating and refrigerated coolingsystem. The cooling system would ordinarily have a power rating ofapproximately 60% of the heating device and so in this example, thewater chilling system would have a power rating of about 36% of theheating device. In general terms, the water chilling system could have apower rating of at least less than 60% of the heating device, or of atleast less than 50% of the heating device, or of at least less than 45%of the heating device, or of at least less than 40% of the heatingdevice, or, as indicated above, about 36% of the heating device.

Further development of the invention has extended to the use of heatedwater for heating purposes with further associated benefits as describedherein.

Applicant is not aware of a water chilling system being used in the pastin ducted heating and cooling systems. Moreover, only after testing wasit evident that the use of a water chilling system in a ducted heatingand cooling system provided the significant benefits that the presentinvention provides. Water chilling systems have been employed in thepast for cooling purposes, but not as part of a ducted heating andcooling system to the applicant's knowledge as refrigerated airconditioning has always been the preference for pairing with gas heatingin ducted systems.

BRIEF DESCRIPTION OF DRAWINGS

In order that the invention may be more fully understood, someembodiments will now be described with reference to the figures inwhich:

FIG. 1 is a schematic illustration of a heating and cooling system for abuilding space, according to one embodiment of the invention.

FIG. 2 illustrates the arrangement of FIG. 1 with a photovoltaic (PV)solar collection system 40 added.

FIG. 3 illustrates the arrangement of FIG. 2 with a storage tank and asolar hot water system added.

FIG. 4 is a schematic illustration of a heating and cooling system for abuilding space, according to another embodiment of the invention.

FIG. 5 is a data table to compare cooling characteristics of a heatingand cooling system according to an embodiment of the invention asillustrated in FIG. 4, with a refrigerated air-conditioning system ofthe prior art.

DETAILED DESCRIPTION

FIG. 1 illustrates schematically, a ducted heating and cooling system 10for heating or cooling a building space according to a first embodimentof the invention. The heating and cooling system 10 is applied to abuilding 11 which in FIG. 1, is a domestic dwelling (shown schematicallyonly). The heating and cooling system 10 is partly located within theroof space 12 of the building 11 and the building space to be heated isthe space 13 below the ceiling 14.

The heating and cooling system 10 includes the components that arehoused within the roof space 12, as well as further components which arelocated outside of the building 11. The system 10 thus includes aheating/cooling facility 15 and a fan/coil unit 16, comprising a coil 17and a fan 18. The coil 17 and the fan 18 are connected together and thusform an integrated unit 16, although for clarity, they are shownseparately or disconnected in FIG. 1 but within an overall housing 19.The heating/cooling facility 15 can include a water chiller or likewater cooler.

Ducting is provided in connection with the fan/coil unit 16 and theducting comprises delivery ducting 20 through which air which has beenheated or cooled in the fan/coil unit 16 is delivered into the buildingspace 13, and return ducting 21 that facilitates the delivery to thefan/coil unit 16, of air to be heated or cooled. The return ducting 21receives air from the space 13 through an air filter 22 and connects toan inlet of the fan/coil unit 16. The delivery ducting 20 connects to anoutlet of the fan/coil unit 16 and branches into several ductingsections to deliver heated or cooled air through the ceiling 14 and intothe space 13.

The heating or cooling effect that is to be achieved is achieved by wayof the delivery of heated or cooled/chilled water from theheating/cooling facility 15 through delivery conduit 25 that fluidlyconnects the heating/cooling facility 15 to the coil 17 of the fan/coilunit 16. As an example, heated water that is delivered through theconduit 25 circulates through the coil 17 and at the same time, the fan18 draws air through the filter 22 and the return ducting 21 anddisplaces that air through and about the coil 17. The air is thereforeheated as it passes through or about the coil 17 and it thereafterenters the delivery ducting 20 for discharge through that ducting intothe space 13. The water delivered from the heating/cooling facility 15returns after discharge from the coil 17 via the return conduit 26 backto the heating/cooling facility 15 for reheating or re-cooling. The coil17 is thus in a closed loop fluid connection with the heating/coolingfacility 15 via the delivery and return conduits 25 and 26.

In the same way, when the space 13 is to be cooled, the heating/coolingfacility 15 cools water and delivers that water through the deliveryconduit 25 to the coil 17, where it passes through the coil 17 and coolsair that is driven through and about the coil 17 via the fan 18. Thatair is drawn through the return ducting 21 and discharged into thedelivery ducting 20 as described above in relation to heated air. Aone-way valve 27 is connected into the delivery conduit 25 adjacent theheating/cooling facility 15 and prevents the return of water to theheating/cooling facility 15 which has already been discharged from thatfacility into the delivery conduit 25 towards the coil 17.

It is envisaged that the heating/cooling facility 15 will be able tosupply water which is sufficiently heated or cooled to the coil 17 ofthe fan/coil unit 16 for the building space 13 to likewise besufficiently heated or cooled subject to the size of the space 13 andthe capacity of the heating/cooling facility 15. However, it is anoption to provide additional capacity for heating or cooling and forexample, FIG. 1 shows an additional appliance 30 that connects into thedelivery and return conduits 25, 26 and this appliance 30 can beoperated if the heating or cooling requirements for the space 13 exceedthe capacity of the heating/cooling facility 15.

The appliance 30 can be a heating appliance in the form of an instantgas hot water heater that can be operated in circumstances where thefacility 15 cannot supply sufficiently heated water to the coil 17 toheat the space 13 sufficiently. The arrangement can be such that theappliance 30 can draw water from the return conduit 26, heat that waterand return it to the delivery conduit 25 in addition to heated waterthat is already being supplied to the delivery conduit 25 via theheating/cooling facility 15. Of course the appliance 30 could be acooling appliance and operate in the same manner with the exception thatit provides cooled or chilled water, rather than heated water.

In alternative arrangements, the heating/cooling facility 15 can provideonly one of the heating or cooling functions, so that it becomes aheating or cooling facility but not both. Whichever of the heating orcooling functions that the facility 15 does not provide, can then beprovided by the appliance 30. in this arrangement, a source valve 31 isprovided in the delivery conduit 25 to connect to the delivery conduit32 that extends from the appliance 30 and the operational controls ofthe system 10 can control the valve 31, so that it opens to either ofthe facility 15 or the appliance 30 depending on the heating or coolingrequirements that have been selected by the operator. It is notnecessary to include a similar valve in connection with the returnconduit 33 of the appliance 30 where it connects to the return conduit26, as water returning through the conduit 26 will be diverted towhichever of the facility 15 or the appliance 30 is operating, becauseonly that facility or appliance will be pumping water back through thereturn conduit 25 (via the return conduit 32 in respect of the appliance30). That is, with the source valve 31 closed to the facility 15 andopen to the appliance 30, water returning through the return conduit 26will divert through the return conduit 33 and enter the appliance 30rather than returning to the facility 15, because the facility 15 willhave no capacity to receive return water. Likewise, the reverse occurswhen the valve 31 is open to the facility 15 and closed to the appliance30.

The heating and cooling system 10 is ideally controlled by a controller35 that is mounted on a wall 36 of the building 11. The controller 35can be of a standard form which includes the ability to select heatingor cooling, the temperature to which the space 13 is to be heated orcooled and timing options for heating and cooling to take place. Thecontroller 35 can communicate with the system 10 in order to cause thefacility 15, and optionally the appliance 30, to operate in the mannerrequired to deliver heated or cooled water to the fan/coil unit 16 andalso for the fan 18 to be operated at a suitable speed.

FIG. 2 illustrates the arrangement of FIG. 1 but advantageously has beencreated for use with a photovoltaic (PV) solar collection system 40. Thesame reference numerals are used in FIG. 2 for components and parts thatare common to FIGS. 1 and 2.

Added to the system 10 is a PV solar panel array 41 (only one panel ormodule of which is shown) which is electrically connected to an inverter42 and to a main electrical circuit box 43. A current sensor 44 ispositioned between the inverter 42 and the circuit box 43.

The obvious benefit of the arrangement of FIG. 2 is via the use of solargenerated electricity to fully or partially power the heating/coolingfacility 15 and/or the appliance 30. Further advantageously, the use ofa current sensor 44 enables the system 40 to determine whether thecurrent being produced by the PV array 41 is sufficient to power or atleast contribute to powering whichever of the facility 15 or theappliance 30 is operating to heat or cool water.

In circumstances where there is sufficient power for the PV array 41 tofully power the facility 15 or the appliance 30, then the facility 15 orthe appliance 30 could be automatically operated at that time (whichwould always be during the day) to either heat or cool the interiorspace 13 as required without the need to draw electricity from the mainssupply and with the aim to minimise the need to later heat or cool theinterior space 13 when solar collection is not available. This meansthat, particularly if the space 13 is well insulated, the heating orcooling affect achieved during the day might remove the need, or atleast alleviate the need for further heating or cooling at night time.This of course would require the facility 15 or the appliance 30 toprovide electric heating or cooling.

The system 40 could be an already installed system that could beconnected up to the system 10 with relative ease.

FIG. 3 is a further modification of the arrangements of FIGS. 1 and 2and so for FIG. 3, the same reference numerals are used for componentsand parts that are common to the earlier figures.

In addition to the heating and cooling system 10 and the PV system 40 ofFIGS. 1 and 2, the arrangement of FIG. 3 further includes a waterstorage tank 50 and a solar hot water system 51.

By the arrangement of FIG. 3, heated or cooled water can be stored inthe tank 50, so that the heated or cooled water can be produced duringthe day using solar energy collected by the PV array 41 and used laterduring the night.

Likewise, water can be heated through the system 51 and delivered to thetank 50, again for use, predominately in cooler weather, to provide asource of heated water, so that the heating requirements of the facility15 are reduced. A pump 52 is provided to pump water from the tank 50through conduit 53 for heating within the system 51 and then return tothe tank 50 via the conduit 54. One-way valves 55 and 56 control thedirection of flow of water from each of the facility 15 and the system51 into the tank 50.

It can be seen in the FIG. 3 arrangement that the delivery and returnconduits 25, 26 are in fluid communication with the tank 50. Thus, thetank 50 becomes the primary source of heated or cooled water which isproduced by the facility 15 and/or the system 51.

The arrangements of FIGS. 1 to 3 advantageously, as discussed earlierherein, can reduce the energy consumption required to heat or cool abuilding space. The arrangements have been developed for use withoutincluding refrigerated air conditioning appliances. The systemsdisclosed herein are expected to be easily retrofitted to existingheating and cooling systems, and can also be installed as a completelynew system. The adaptability of the system for use with solarcollection, either through solar PV arrays or hot water solarcollectors, gives the system flexibility and attractiveness to consumerswho wish to minimise mains electricity consumption for both cost andenvironmental reasons.

FIG. 4 illustrates schematically, a ducted heating and cooling systemfor heating or cooling a building space according to a second embodimentof the invention.

The heating and cooling system 110 is applied to a building 111 withinwhich is a building space 112 which is to be heated or cooled by thesystem 110.

The heating and cooling system 100 includes a gas heating device 115 anda cooling device that comprises a cooling coil 116 and a water chiller117. The water chiller can for example be a 7 kW unit coupled with a 20kW heating device 115. Other combinations as discussed earlier hereincan alternatively be adopted.

Ducting 120 is provided in communication with the building space 112 andwith each of the heating device 115 and the coil 116. The ducting 120comprises a return ducting section 121 that includes an inlet 122 thatopens into the building space 112 and which connects to an inlet of theheating device 115. Airflow into the heating device 115 takes placethrough the return ducting section 121. The ducting 120 furthercomprises a connecting ducting section 123 that connects between anoutlet of the heating device 115 and an inlet of the coil 116. Finally,the ducting 120 comprises a delivery ducting section 124 that connectsto an outlet of the coil 116 and which includes outlet branches 125 and126 that communicate with the building space 112.

It is of course to be appreciated that the ducting 120 illustrated inFIG. 4 is of a schematic nature only and in practice, the ducting 120could include more than one return ducting section 121, and additionaldelivery ducting sections 124 and branches 125 and 126.

The water chiller 117 is in closed loop connection with the coil 116 viadelivery conduit 128 and return conduit 129. The passage of water intherefore quarantined to remain between the coil 116 and the waterchiller 117.

While not illustrated in FIG. 4, the heating device 115 is a gas heatingdevice and includes an integrated fan. Accordingly, a separate fan isnot illustrated in FIG. 4, but additional fans could be provided asrequired in any of the ducting sections 121, 123 or 124.

The operation of the heating and cooling system 110 will now bedescribed. If the building space 112 is to be heated, then the heatingdevice 115 is operated. Because the system is set up so that only one ofthe heating and cooling devices can be operated at one time, with theheating device 115 operational, the cooling device is inoperative ordisabled. With the heating device 115 operating, the integrated fan ofthat device draws air in through the inlet 122 into the return ductingsection 121 and through the heating device 115 where the air that entersthe heating device 115 is heated. The heated air is pushed through theconnecting ducting section 123, the coil 116 and into the deliveryducting section 124 where it exits the ducting 120 through the outlets130 and 131 of the branches 125 and 126.

The flow of air through the ducting 120 is continuous, by virtue of airbeing drawn into the return ducting section 121 and being discharged outof the delivery ducting section 124. The temperature inside the buildingspace slowly increases as the air within the building space cyclesthrough the heating device 115. Once the temperature within the buildingspace reaches the desired temperature, adjustments to the fan speed, orthe heat output of the heating device 115, or both can be made tomaintain the temperature.

Importantly, the heated air that exits the heating device 115 is notsubject to any cooling by passage or travel through the coil 116,because the cooling device is inoperative or disabled and so there isnot flow of chilled water to the coil 116.

In the alternative, when the temperature within the building space 112is to be cooled, then the heating device 115 is rendered inoperative oris disabled, but the fan is operated. This causes air to flow throughthe ducting 120 in the same manner as during the heating cycle and thusair flows through the heating device 115 and the coil 116 as describedabove. However, in order for a cooling function to take place, thechiller 117 supplies chilled water through the delivery conduit 128 tothe coil 116 and air that is delivered into the coil 116 via the fan ofthe heating device 115 is cooled for discharge into the building space112 via the delivery ducting section 124. Again, the air within thebuilding space 112 is cycled through the ducting 120 by the fan of theheating device 115 until such time as the temperature within thebuilding space 112 reaches the set or desired cooled temperature. Oncethat temperature has been reached, the temperature of the chilled watercan be adjusted, as can the flow of air through the coil 16 to maintainthe cooled temperature.

It has been established that the system of the invention, such asillustrated in FIG. 4, can provide rapid initial temperature reductionwithin a building space. Testing has been conducted to compare a systememploying a conventional refrigerated air-conditioning unit to a unitaccording to the invention in which a water chiller that was about 40%smaller in terms of kW output compared to the conventional refrigeratedair-conditioning unit, was installed. The results of that testing areillustrated in FIG. 5 and show that temperature cooling from an initialtemperature of 31° C. to a lower temperature of 26° C. occurred morequickly and at a lower energy output in the system according to theinvention as compared to a system incorporating a conventionalrefrigerated air-conditioning unit.

The attached table of FIG. 5 gives the actual testing data of arudimentary test that the applicant has undertaken and compares aconventional air-conditioning unit known as a 12 kW air-conditioner tothe 7 kW unit referred to above. The table of FIG. 5 shows that use ofthe water chiller was able to reduce the building space temperature from31° to 26° within 3 minutes. That compared to 6.1 minutes for therefrigerated air-conditioning unit. Moreover, the water chiller had anenergy usage of 0.17 kW/h as compared to the air-conditioning unit powerusage of 0.37 kW/h.

The testing of the table in FIG. 5 was conducted with the water chiller117 being pre-cooled which provided very fast initial cooling.

In relation to heating, the systems according to the invention can useheating devices which are already in use in heating systems for domesticdwellings and commercial buildings and it is expected that the heatingcapacity of a system according to the invention will be in line with theheating capacity of units already in existence.

The heating and cooling system 110 is expected to provide thesignificant advantages as stated earlier herein in relation to improvedenergy efficiency and lower running costs, reduced capital cost, reducedmaintenance cost environmental benefits.

Where any or all of the terms “comprise”, “comprises”, “comprised” or“comprising” are used in this specification (including the claims) theyare to be interpreted as specifying the presence of the stated features,integers, steps or components, but not precluding the presence of one ormore other features, integers, steps or components.

Those skilled in the art will appreciate that the invention describedherein is susceptible to variations and modifications other than thosespecifically described. It is understood that the invention includes allsuch variations and modifications which fall within the spirit and scopeof the present invention.

1. A heating and cooling system for heating or cooling air within abuilding space, the system including: a. a water heating facility toheat water, b. a water chiller to cool or chill water, c. a coil influid connection with the water heating facility and the water chillerand through which air can be passed for heating or cooling, d. a fan fordriving air through the coil, and e. ducting comprising delivery ductingthrough which air which has been heated or cooled by the coil can bedelivered into the building space and return ducting through which airwithin the building space can be returned to the coil for heating orcooling, the system being operable such that the water heating facilityor the water chiller supplies either heated or cooled or chilled waterto the coil and the fan causes air to flow through the return ductingfrom the building space, then through the coil, and then through thedelivery ducting for delivery into the building space.
 2. A systemaccording to claim 1, the water heating facility and the water chillerbeing integrated into a single unit.
 3. A system according to claim 1,the water heating facility and the water chiller being separate fromeach other.
 4. A system according to claim 1, the fan and coil beingincluded in a single complete fan/coil unit.
 5. A system according toclaim 1, the fan being connected to the return ducting or beingpositioned on the side of the return ducting and the coil beingconnected to the delivery ducting or being positioned on the side of thedelivery ducting, so that the fan is positioned upstream of the coilunit.
 6. A system according to claim 1, further including a photovoltaic(PV) solar collection system for providing electrical power to the waterheating facility.
 7. A system according to claim 1, further including awater storage tank.
 8. A system according to claim 7, the water heatingfacility and the water chiller being in fluid communication with thewater storage tank to deliver heated or cooled water to the storage tankfor storage.
 9. A system according to claim 1, further including a solarhot water system and the solar hot water system being in fluidcommunication with the water storage tank to deliver heated water to thestorage tank for storage.
 10. A system according to claim 1, the waterchilling system having a power rating of at least less than 60% of theheating device, or of at least less than 50% of the heating device, orof at least less than 45% of the heating device, or of at least lessthan 40% of the heating device, or about 36% of the heating device. 11.A method of cooling a building space, the method involving installing aheating and cooling system according to claim 1 and thereafter operatingthe cooling device.
 12. A method of cooling a building space accordingto claim 11, the method including chilling the water of the waterchiller to a low temperature at the commencement of a cooling operation,and thereafter operating the water chiller to deliver chilled water tothe coil.
 13. A method of cooling a building space according to claim11, including controlling the cooled temperature within the buildingspace by fan speed to adjust the airflow across or circulating throughthe coil.
 14. A heating and cooling system for heating or cooling airwithin a building space, the system including: a. a heating device whichis operational to heat air passing through it, and a cooling device, b.a fan, and c. ducting comprising delivery ducting through which airheated by the heating device or cooled by the cooling device can bedelivered into the building space and return ducting through which airwithin the building space can be returned to the heating and coolingdevices, the cooling device comprising a water chilling system having acoil which is operational to cool air passing through it and each of theheating device and the coil having an air inlet and an air outlet, theair inlet of one of the heating device and the coil being connected tothe return ducting, and the air outlet of that device being connected tothe air inlet of the other of the heating device and the coil, the waterchilling system further including a water chiller which is in closedloop connection with the coil to deliver chilled water to the coil andto receive water from the coil, the system being operable such thatoperation of the fan causes air flow through the return ducting from thebuilding space, then through the heating device and the coil, and thedelivery ducting for delivery into the building space, and the systemfurther being operable such that only one of the heating and the coolingdevices is operational at any one time.
 15. A system according to claim14, the air inlet of the heating device being connected to the returnducting, so that air that is returned from the building space flows intothe heating device first and then into the coil of the cooling deviceand the air inlet of the coil being connected to the return ducting, sothat air that is returned from the building space flows into the coilfirst and then into the heating device.
 16. A system according to claim14, the heating device being positioned upstream of the cooling deviceso that the heating device is connected to the return ducting.
 17. Asystem according to claim 14, the water chilling system having a powerrating of at least less than 60% of the heating device, or of at leastless than 50% of the heating device, or of at least less than 45% of theheating device, or of at least less than 40% of the heating device, orabout 36% of the heating device.
 18. A method of cooling a buildingspace, the method involving installing a heating and cooling systemaccording to claim 14 and thereafter operating the cooling device.
 19. Amethod of cooling a building space according to claim 18, the methodincluding chilling the water of the water chiller to a low temperatureat the commencement of a cooling operation, and thereafter operating thewater chiller to deliver chilled water to the coil.
 20. A method ofcooling a building space according to claim 18, including controllingthe cooled temperature within the building space by fan speed to adjustthe airflow across or circulating through the coil.